You've heard about smart homes where the toaster talks to the smoke detector, but what makes it all connect? These FAQs help explain it all

You've heard the term and probably read stories about smart homes where the toaster talks to the smoke detector. But what makes it all connect? When will it become mainstream, and will it work? These frequently asked questions help explain it all.

What is the Internet of things?

There is no agreed-upon definition, but there is a test for determining whether something is part of the IoT: Does one vendor's product work with another's? Does a door lock by one vendor communicate with a light switch by another vendor, and do you want the thermostat to be part of the conversation?

Here's the scenario: As you approach the front door of your house, a remote control built into your key unlocks the door. The door's wireless radio messages the network, which prompts the hall light to turn on. The house thermostat, which was lowered after you left for work, returns to a comfort zone. Everything is acting in concert, which brings us to the elegant definition of IoT by Paul Williamson, director of low power wireless for semiconductor maker CSR: "A true Internet of things is coordination between multiple devices."

What makes the Internet of things almost human?

In a word: Sensors. Many IoT devices have sensors that can register changes in temperature, light, pressure, sound and motion. They are your eyes and ears to what's going on the world. Before we talk about what they do, let's describe them. These sensors are part of a device category called a microelectromechanical system (MEMS) and are manufactured in much the same way microprocessors are manufactured, through a lithography process. These sensors can be paired with an application-specific integrated circuit or an ASIC. This is a circuit with a limited degree of programming capability and is hardwired to do something specific. It can also be paired with microprocessor and will likely be attached to a wireless radio for communications.

Can you give an example of how IoT sensors work?

Here's the scene: You are away on vacation and the house is empty. A moisture sensor detects water on the basement floor. That sensor finding is processed by an app, which has received another report from a temperature sensor that detects the flow of water in the main water pipe. (When water flows, it takes away heat and lowers the temperature).

That both sensors are detecting anomalies is cause for concern. A high rate of flowing water may signal a burst pipe, triggering an automated valve shutoff; a slight water flow might be a running toilet, and the water on the basement floor by routine leakage from a heavy rain. In either case, you get a machine-generated message describing the findings.

Here's how you investigate. Via a mobile app, you get two one-time codes to unlock your front door, one for your neighbor and another for a plumber. When the door is unlocked, a text alert tells you who entered. Having knowledge of the condition of your home may be a big driver of IoT adoption.

How will IoT sensors work in public spaces?

Take parking. Cities are embedding sensors in on-street parking spaces from a company called Streetline that can detect if a car is parked in one. Drivers looking for a parking space use the company's mobile app, which lets them know when a space becomes available. Streetline has also added sound level and surface temperature sensors to help cities determine the best times to apply salt and use noise sensors to ensure compliance with ordinances.

In the public arena, a smartphone can double as a sensor. In Boston, as people drive down a road, the phone's accelerometer sensor will keep track of bumps. An accelerometer can tell up from down, but more precisely it measures acceleration. All it took to turn a smartphone into a road condition monitoring tool, was an app that used its existing sensor in a new way.

Do you want your bathroom scale to talk to your refrigerator?

The IoT opens up a lot of opportunity for creative app writers. Let's start with a smart refrigerator. You buy your groceries online and have them delivered to your home. It has now become advantageous for grocers and food product makers to add RFID tags to their products. The refrigerator knows what is inside via weight-sensitive shelves and expiration dates. It can also help you keep a grocery list, automate orders and provide nutritional information.

For instance, let's say you decide to take a pint of Ben and Jerry's ice cream out of the freezer. When that happens, a connected wireless speaker announces, loudly: "Please reconsider this selection. As requested, here is your most recent weight and BMI." The wireless speaker is reporting data collected from your bathroom scale. The scale was never designed to communicate with a refrigerator, but an app writer made it so by linking data from the scale and fridge. This scale-fridge-speaker combination may seem silly, but here's the point: In the IoT, app writers now have the ability to connect seemingly disparate things to create new types of functionality.

How do IoT devices communicate?

An IoT device will have a radio that can send and receive wireless communications. IoT wireless protocols are designed to accomplish some basic services: Operate on low power, use low bandwidth and work on a mesh network. Some work on the 2.4 GHz band, which is also used by Wi-Fi and Bluetooth, and the sub-GHz range. The sub-GHz frequencies, including 868 and 915 MHz bands, may have the advantage of less interference.

Why is low power and low bandwidth important in IoT?

Some IoT devices will get power from electrical systems, but many, such as door locks and standalone sensors, will use batteries. These devices send and receive small amounts of information intermittently or periodically. Consequently, the battery life of an IoT device can range from 1.5 years to a decade, if the battery lasts that long. One IoT maker, Insteon, uses both radio and powerline communication, which can send data over existing electrical wiring as well as via a radio, which it says will offer an increased measure of reliability.

What is a mesh network?

Devices in a mesh network connect directly with one another, and pass signals like runners in a relay race. It is the opposite of a centralized network. The transmission range of an IoT device on a mesh network is anywhere from 30 feet to more than 300 feet.

Since mesh network devices can hand-off signals, they have an ability to connect thousands of sensors over a wide area, such as a city, and operate in concert. Mesh networks have the added ability of working around the failure of any individual device. Wireless mesh IoT protocols include the Z-Wave Alliance, the Zigbee Alliance, and Insteon, which also has an alliance of vendors. These protocols aren't directly interoperable, although there are workarounds via hubs (more on this later).

ZigBee is an open protocol, but its critics say that not all of its implementations are necessarily the same. ZigBee runs a certification to ensure standard deployments. Insteon and Z-Wave are proprietary, which may ensure standardization of implementation.

What's the best wireless network for the IoT?

Today, no wireless technology has a dominant market share in IoT applications. Nick Jones, an analyst at research firm Gartner, said more than 10 IoT wireless technologies will "get significant traction" in IoT applications. These wireless technologies include cellular, satellites and new communications such as Weightless, which uses "white space," or unoccupied TV channels. More importantly, no one wireless technology will meet every need and circumstance. A connected car, for instance, will use a cellular network to contact your home network.

Will I need a gateway or hub in the IoT?

A gateway, bridge or hub provides a connection point between your home network and other devices. The hub works with your home router and provides communications to the machines, devices and sensors that are part of your IoT universe. You will want, by default, your Zigbee smart meter to communicate with your Z-Wave or Insteon thermostat. This will also be true for the washing machine that is connected to a smart metering system and starts a wash only when electric rates are at their lowest point. These connections will be established through hubs that support multiple wireless technologies.

SmartThings, for instance, makes a hub that supports both Zigbee and Z-Wave, as well as a platform to build connecting applications. Eventually, these wireless technologies may be included in home routers, set-top boxes from your cable companies, or even devices such as a Google Chromecast.

Won't Bluetooth win in the end?

Bluetooth Low Energy was originally aimed at wearable technology, not the broad IoT market. But in early 2014, CSR, a semiconductor maker, announced a mesh network for Bluetooth, meaning it could now connect to thousands of things.

Bluetooth's ubiquity in mobile devices means that a Bluetooth mesh network as a broad IoT platform will have some advantages. Because Bluetooth is already a feature on smartphones, a smartphone could act as a management hub inside a home. But it's not perfect. A hub will be needed if someone wants to connect with the home network remotely, such as from work.

Do the big consumer product vendors really want an Internet of things?

Skeptics say it's unlikely that all the big vendors will embrace open standards. A more likely outcome for the IoT are technological islands defined by proprietary data interchanges.

Without open standards or open communication protocols, devices on the network won't be able to share data and work in concert. Will Apple develop products that can connect with Samsung products? Will Bosch products communicate with those from Samsung or Sears? Maybe not.

Consumers will be frustrated and will be told that they need to buy into a particular vendor's product partner network to get a full IoT experience.

Can open source force the big vendors to play nice?

Open source advocates are hoping they can avert a fracturing of the IoT. The Linux Foundation, a nonprofit consortium, created the AllSeen Aliance and released a code stack in late 2013 that can be used by any electronics or appliance maker to connect to another product. The alliance hopes that the sheer weight of adoption of this stack, called AllJoyn, will help to push the IoT toward open standards. AllJoyn is agnostic about wireless protocols, and support for Bluetooth LE, ZigBee and Z-Wave can be added easily by the community.

Will the IoT destroy what little privacy you have left?

Privacy advocates are plenty worried about the IoT's impact on consumers. Part of this is due to the arrival of IPv6 addresses, the next generation Internet protocol. It replaces IPv4, which assigned 32-bit addresses, with a total limit of 4.3 billion; IPv6 is 128-bit, and allows for 340 trillion trillion trillion addresses or 340,000,000,000,000,000,000,000,000,000,000,000,000. This makes it possible to assign a unique identifier to anything that's part of the IoT (although not everything needs to be IP addressable, such as light switches). This may enable deep insights into a home. Smart metering systems, for instance, will be able to track individual appliance use.

"Information about a power consumer's schedule can reveal intimate, personal details about their lives, such as their medical needs, interactions with others, and personal habits," warned the Electronic Privacy Information Center, in testimony in late 2013 at a Federal Trade Commission workshop. This is information that may be shared with third parties. At this same FTC workshop, another leading privacy group, the Center for Democracy and Technology, outlined its nightmare scenario.

Light sensors in a home can tell how often certain rooms are occupied, and temperature sensors may be able to tell when one bathes, exercises or leaves the house; microphones can easily pick up the content of conversations. The message is clear: Courts, regulators and lawmakers will be fighting over IoT privacy safeguards for years to come.

Will my smart washer attack me?

Security experts are worried that consumers won't be able to tell the difference between secure and insecure devices on their home network. It will be a threat to enterprise networks as well. These devices, many of which will be cheap and junky and made by who-knows-who overseas, may not have any security of their own.

Security researchers imagine problems, such as the connected toilet, demonstrated at a recent Black Hat conference, which flushed and closed its lid repeatedly. Hackers could create havoc by turning appliances and HVAC systems on and off. Baby monitors have been successfully taken over by outsiders. One advantage that IoT security may have is it's still in its early stages, and the security community has a chance to build IoT systems with a strong measure of protection. Cisco is fishing around for ideas. The company is running a contest (with a June 17 submission deadline) with $300,000 in prize money for ideas for securing the IoT.